PARIS (Reuters) - France issued an implicit criticism of U.S. foreign policy on Thursday, rejecting talk of a "war on terror."

Prime Minister Dominique de Villepin, speaking in parliament, expressed these views on global terrorism, while President Jacques Chirac backed France's claims to the international front rank with a fresh defense of his country's nuclear arsenal.

Villepin noted Chirac's strong opposition to the U.S.-led invasion of Iraq in 2003 and said the Arab state had now sunk into violence and was feeding new regional crises.

"Let us not forget that these crises play into the hands of all extremists," the prime minister said in a debate on the Middle East. "We can see this with terrorism, whether it tries to strike inside or outside our frontiers," he added.

"Against terrorism, what's needed is not a war. It is, as France has done for many years, a determined fight based on vigilance at all times and effective cooperation with our partners.

"But we will only end this curse if we also fight against injustice, violence and these crises," he said.

Villepin's remarks, which came a day after U.S. President George Bush admitted that the CIA had interrogated dozens of terrorism suspects in secret foreign locations, did not explicitly mention the United States.

But his rejection of language employed by Bush, who often uses the expression "war on terror" underlined the longstanding differences between Paris and Washington.

In separate remarks, Chirac stressed that France was committed to maintaining a nuclear arsenal of its own.

He stressed that France was committed to funding continuing research and development into nuclear weapons technology.

"There can be no great ambition without adequate means, that's clear," he said. "The position of countries is never guaranteed. In the 21st century, only those which make science a genuine priority will stay ahead."

Both France and the United States have played down splits opened by the Iraq war, pointing especially to cooperation on attempts by the West to contain Iran's nuclear ambitions.

But differences in tone and style have often resurfaced, notably during the Lebanon crisis, where France initially offered to send just 400 peacekeepers to Lebanon despite vigorously backing calls for an international force.

Villepin's speech in parliament made much of France's leading role in securing a peace agreement in Lebanon backed by the United Nations, which he said had shown the virtues of "listening and dialogue."

"It is the duty of France and Europe to show that the clash of civilizations is not inevitable," he said. "No one retains this wisdom, inherited from our history, as we, French and Europeans, do," he said.